[Form] Precalculated the closure for deciding whether a choice is sel…

…ected (PHP +30ms, Twig +30ms)

src/Symfony/Bridge/Twig/Extension/FormExtension.php

@@ -88,12 +88,18 @@ public function getFilters()
     /**
      * Returns whether a choice is selected for a given form value.
      *
-     * This method exists for the sole purpose that Twig performs (a lot) better
-     * with filters than with methods of an object.
+     * Unfortunately Twig does not support an efficient way to execute the
+     * "is_selected" closure passed to the template by ChoiceType. It is faster
+     * to implement the logic here (around 65ms for a specific form).
      *
-     * To give this some perspective, I'm currently testing this on a form with
-     * a large list of entity fields. Using the filter is around 220ms faster than
-     * accessing the method directly on the object in the Twig template.
+     * Directly implementing the logic here is also faster than doing so in
+     * ChoiceView (around 30ms).
+     *
+     * The worst option tested so far is to implement the logic in ChoiceView
+     * and access the ChoiceView method directly in the template. Doing so is
+     * around 220ms slower than doing the method call here in the filter. Twig
+     * seems to be much more efficient at executing filters than at executing
+     * methods of an object.
      *
      * @param ChoiceView   $choice        The choice to check.
      * @param string|array $selectedValue The selected value to compare.
@@ -104,7 +110,11 @@ public function getFilters()
      */
     public function isChoiceSelected(ChoiceView $choice, $selectedValue)
     {
-        return $choice->isSelected($selectedValue);
+        if (is_array($selectedValue)) {
+            return false !== array_search($choice->value, $selectedValue, true);
+        }
+
+        return $choice->value === $selectedValue;
     }
 
     /**

src/Symfony/Bridge/Twig/Tests/Extension/FormExtensionDivLayoutTest.php

@@ -18,6 +18,7 @@
 use Symfony\Bridge\Twig\Tests\Extension\Fixtures\StubTranslator;
 use Symfony\Bridge\Twig\Tests\Extension\Fixtures\StubFilesystemLoader;
 use Symfony\Component\Form\FormView;
+use Symfony\Component\Form\Extension\Core\View\ChoiceView;
 use Symfony\Component\Form\Tests\AbstractDivLayoutTest;
 
 class FormExtensionDivLayoutTest extends AbstractDivLayoutTest
@@ -105,6 +106,39 @@ public function testThemeBlockInheritanceUsingExtend()
         );
     }
 
+    public function isChoiceSelectedProvider()
+    {
+        // The commented cases should not be necessary anymore, because the
+        // choice lists should assure that both values passed here are always
+        // strings
+        return array(
+//             array(true, 0, 0),
+            array(true, '0', '0'),
+            array(true, '1', '1'),
+//             array(true, false, 0),
+//             array(true, true, 1),
+            array(true, '', ''),
+//             array(true, null, ''),
+            array(true, '1.23', '1.23'),
+            array(true, 'foo', 'foo'),
+            array(true, 'foo10', 'foo10'),
+            array(true, 'foo', array(1, 'foo', 'foo10')),
+
+            array(false, 10, array(1, 'foo', 'foo10')),
+            array(false, 0, array(1, 'foo', 'foo10')),
+        );
+    }
+
+    /**
+     * @dataProvider isChoiceSelectedProvider
+     */
+    public function testIsChoiceSelected($expected, $choice, $value)
+    {
+        $choice = new ChoiceView($choice, $choice . ' label');
+
+        $this->assertSame($expected, $this->extension->isChoiceSelected($choice, $value));
+    }
+
     protected function renderEnctype(FormView $view)
     {
         return (string) $this->extension->renderer->renderEnctype($view);

src/Symfony/Bundle/FrameworkBundle/Resources/views/Form/choice_widget_options.html.php

@@ -6,6 +6,6 @@
             <?php echo $formHelper->block('choice_widget_options', array('choices' => $choice)) ?>
         </optgroup>
     <?php else: ?>
-        <option value="<?php echo $view->escape($choice->value) ?>"<?php if ($choice->isSelected($value)): ?> selected="selected"<?php endif?>><?php echo $view->escape($translatorHelper->trans($choice->label, array(), $translation_domain)) ?></option>
+        <option value="<?php echo $view->escape($choice->value) ?>"<?php if ($is_selected($choice->value, $value)): ?> selected="selected"<?php endif?>><?php echo $view->escape($translatorHelper->trans($choice->label, array(), $translation_domain)) ?></option>
     <?php endif ?>
 <?php endforeach ?>

src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php

@@ -90,6 +90,20 @@ public function buildView(FormView $view, FormInterface $form, array $options)
             'empty_value'       => null,
         ));
 
+        // The decision, whether a choice is selected, is potentially done
+        // thousand of times during the rendering of a template. Provide a
+        // closure here that is optimized for the value of the form, to
+        // avoid making the type check inside the closure.
+        if ($options['multiple']) {
+            $view->vars['is_selected'] = function ($choice, array $values) {
+                return false !== array_search($choice, $values, true);
+            };
+        } else {
+            $view->vars['is_selected'] = function ($choice, $value) {
+                return $choice === $value;
+            };
+        }
+
         // Check if the choices already contain the empty value
         // Only add the empty value option if this is not the case
         if (0 === count($options['choice_list']->getIndicesForValues(array('')))) {